Aim. Aging is associated with a reduction on heart rate variability (HRV) and working capacity. Aim of this study was to evaluate in a group of elite master athletes the effect of a lifelong history of endurance running on HRV and exercise working capacity.Methods. Twenty athletes (males, age 68.5±4.5 years) who practiced endurance running for at least 40 years, and 20 age-sex-matched control subjects with sedentary lifestyle were studied. All the participants underwent a maximal stepwise electrocardiogram (ECG) on effort (work-rate increments of 25 Watts every 2 min) and a 24-hour ECG monitoring.Results. All the time domain measures of HRV and the LF and HF powers were significantly higher in elderly athletes than in sedentary subjects (P<0.001), while the LF/HF ratio was comparable between the 2 groups. Athletes exhibited significantly higher workload than controls (1 610±489 vs 687±236 W, P<0.0001). Both the groups achieved, at maximum workload, similar heart rate (142±10 vs 138±18 bpm, ns), systolic blood pressure (226±18 vs 220±16 mmHg, ns), and rate-pressure product (32 596±2 952 vs 30 838±3 675, ns). Maximum work-rate attained in athletes was 225 W. By contrast, none of the controls reached a work-rate higher than 150 W. In the whole group we also showed a positive correlation between the time domain HRV parameter SDNN and maximum workload (r=0.58, P<0.001).Conclusion. Long-term endurance training induces in elderly subjects an increased HRV and a higher exercise working capacity, which are well-established predictors of cardiovascular and overall mortality.